Pancreatic cancer is the fourth leading cause of cancer death in the U.S. and has an extremely poor prognosis, with a median survival of 3 months. Moreover, pancreatic cancer is resistant to both chemotherapy and radiotherapy. Increasing evidence suggests that many solid tumors arise specifically in the stem cell population located within cancer tissues. Identification of tumor initiating stem cells from breast, brain, colonic and pancreatic tumors has recently been described, and has accelerated interest in the stem cell origin of cancer. A major obstacle however, has been the lack of definitive markers to identify and isolate "pure" populations of cancer stem/progenitor cells. We have determined that the recently reported novel intestinal stem cell marker DCAMKL-1 is expressed in normal mouse pancreatic islet and main pancreatic ductal epithelial cells, and in tissues from the P48Cre-LSL-KRASG12D pancreatic cancer mouse model and in human pancreatic tumors. These data suggest that DCAMKL-1 may be a novel marker of normal and cancer pancreatic stem cells. The central hypotheses of this proposal are 1) stem/progenitor cells are a key subpopulation of cells within the normal pancreas and in pancreatic cancers, and 2) identification and isolation of pancreatic cancer stem/progenitor cells is critical to the development of novel targeted therapeutic paradigms for tumor eradication. Following isolation of putative pancreatic stem/progenitor cells by FACS using DCAMKL-1, we can now demonstrate self-renewal and spheroid formation in vitro and development of epithelial structures in mouse isografts. To test these hypotheses we propose the following specific aims: 1. To isolate and characterize normal pancreatic stem/progenitor cells from the normal adult mouse pancreas. 2. To isolate and determine the molecular features of pancreatic cancer stem cells derived from animal model of pancreatic neoplasia and 3. To isolate pancreatic cancer stem cells from human pancreatic tumors and recapitulate the tumors in serial xenografts in immunodeficient mice. These studies represent a mechanistic approach to defining the characteristic features of normal and pancreatic cancer stem/progenitor cells. Identification and elucidation of the unique molecular signatures and signaling pathways that regulate their proliferation and differentiation should aid in the development of novel therapeutic approaches for treating pancreatic cancer. PUBLIC HEALTH RELEVANCE: These studies will provide a detailed quantitative assessment of the molecular features of pancreatic stem/progenitors isolated from the normal mouse pancreas, neoplastic model of pancreatic cancer in animals and in human pancreatic cancer. Collectively these studies should provide new insights into the roles of stem/progenitor cells in pancreatic cancer, pancreatic regeneration, and perhaps diabetes.